793 resultados para long-run dynamics


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper studies the long-run impact of HIV / AIDS on per capita income and education. We introduce a channel from HIV / AIDS to long-run income that has been overlooked by the literature, the reduction of the incentives to study due to shorter expected longevity. We work with a continuous time overlapping generations mo deI in which life cycle features of savings and education decision play key roles. The simulations predict that the most affected countries in Sub-Saharan Africa will be in the future, on average, a quarter poorer than they would be without AIDS, due only to the direct (human capital reduction) and indirect (decline in savings and investment) effects of life-expectancy reductions. Schooling will decline on average by half. These findings are well above previous results in the literature and indicate that, as pessimistic as they may be, at least in economic terms the worst could be yet to come.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Using a sequence of nested multivariate models that are VAR-based, we discuss different layers of restrictions imposed by present-value models (PVM hereafter) on the VAR in levels for series that are subject to present-value restrictions. Our focus is novel - we are interested in the short-run restrictions entailed by PVMs (Vahid and Engle, 1993, 1997) and their implications for forecasting. Using a well-known database, kept by Robert Shiller, we implement a forecasting competition that imposes different layers of PVM restrictions. Our exhaustive investigation of several different multivariate models reveals that better forecasts can be achieved when restrictions are applied to the unrestricted VAR. Moreover, imposing short-run restrictions produces forecast winners 70% of the time for the target variables of PVMs and 63.33% of the time when all variables in the system are considered.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Includes bibliography

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Includes bibliography

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We numerically investigate the long-term dynamics of the Saturn's small satellites Methone (S/2004 S1), Anthe (S/2007 S4) and Pallene (S/2004 S2). In our numerical integrations, these satellites are disturbed by non-spherical shape of Saturn and the six nearest regular satellites. The stability of the small bodies is studied here by analyzing long-term evolution of their orbital elements.We show that long-term evolution of Pallene is dictated by a quasi secular resonance involving the ascending nodes (12) and longitudes of pericentric distances (pi) of Mimas (subscript 1) and Pallene (subscript 2), which critical argument is pi(2) - pi(1) - Omega(1) + Omega(2) Long-term orbital evolution of Methone and Anthe are probably chaotic since: i) their orbits randomly cross the orbit of Mimas in time scales of thousands years); ii) long-term numerical simulations involving both small satellites are strongly affected by small changes in the initial conditions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We estimate the underpricing and long-run performance of Swiss initial public offerings (IPOs) from 1983 to 2000. The average market adjusted initial return is 34.97%. To examine the long-run performance of Swiss IPOs, we compute buy-and-hold abnormal returns, skewness-adjusted wealth ratios, and cumulative abnormal returns using 120 months of secondary market returns. In contrast to previous findings for the U.S. and Germany, we do not find strong evidence for a distinct IPO effect. We attribute long-run underperformance to the fact that IPO firms tend to be small firms. It virtually vanishes when we use a small capitalization index as a benchmark. In spite of distinct economic implications and statistical properties, our basic results are similar for all performance measures applied.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The shortcomings of conventional discounting, especially in the context of long-run environmental problems, have been extensively discussed in the literature. Recently, hyperbolic discounting, i. e. discounting at declining instead of constant discount rates, has attracted a lot of interest among both scientists and politicians. Although there are compelling arguments for employing hyperbolic discounting, there are also pitfalls, which have to be pointed out. In this paper I show that the problem of time-inconsistency, an inherent characteristics of hyperbolic discounting, leads to a potential clash between economic efficiency and intergenerational equity. As an example, I refer to the weak progress in the controlling of greenhouse gas emissions under the Kyoto protocol. As the problem of time-inconsistency cannot be solved on economic grounds alone, there is a need for an intergenerational moral commitment.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper explores whether a significant long-run relationship exists between money and nominal GDP and between money and the price level in the Venezuelan economy. We apply time-series econometric techniques to annual data for the Venezuelan economy for 1950 to 1996. An important feature of our analysis is the use of tests for unit roots and cointegration with structural breaks. Certain characteristics of the Venezuelan experience suggest that structural breaks may be important. Since the economy depends heavily on oil revenue, oil price shocks have had important influences on most macroeconomic variables. Also since the economy possesses large foreign debt, the world debt crisis that exploded in 1982 had pervasive effects on the Venezuelan economy. Radical changes in economic policy and political instability may have also significantly affected the movement of the macroeconomy. We find that a long-run relationship exists between narrow money (M1) and nominal GDP, the GDP deflator, and the CPI when one makes allowances for one or two structural breaks. We do not find such long-run relationships when broad money (M2) is used.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Most monetary models make use of the quantity theory of money along with a Phillips curve. This implies a strong correlation between money growth and output in the short run (with little or no correlation between money and prices) and a strong long run correlation between money growth and inflation and inflation (with little or no correlation between money growth and output). The empirical evidence between money and inflation is very robust, but the long run money/output relationship is ambiguous at best. This paper attempts to explain this by looking at the impact of money growth on firm financing.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper outlines a process for teaching long-run neutrality of money, drawing an analogy between equity markets and the money market. The key points in the discussion include the following: (1) What is the price of money? (2) Why does the long-run demand for money trace out a rectangular hyperbola? (3) Why does the slow adjustment of goods and service prices to changes in the stock of money lead to a different short-run demand for money? and (4) Why does a successful currency reform generate similar short-run movements in the price of money as movements in equity share prices after a change in the supply of shares? I have used this approach successfully for over 30 years at all levels, wherever I need to discuss the money market in a macroeconomic model.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Recent evolution experiments have revealed that marine phytoplankton may adapt to global change, for example to ocean warming or acidification. Long-term adaptation to novel environments is a dynamic process and phenotypic change can take place thousands of generations after exposure to novel conditions. Using the longest evolution experiment performed in any marine species to date (4 yrs, = 2100 generations), we show that in the coccolithophore Emiliania huxleyi, long-term adaptation to ocean acidification is complex and initial phenotypic responses may revert for important traits. While fitness increased continuously, calcification was restored within the first 500 generations but later reduced in response to selection, enhancing physiological declines of calcification in response to ocean acidification. Interestingly, calcification was not constitutively reduced but revealed rates similar to control treatments when transferred back to present-day CO2 conditions. Growth rate increased with time in controls and adaptation treatments, although the effect size of adaptation assessed through reciprocal assay experiments varied. Several trait changes were associated with selection for higher cell division rates under laboratory conditions, such as reduced cell size and lower particulate organic carbon content per cell. Our results show that phytoplankton may evolve phenotypic plasticity that can affect biogeochemically important traits, such as calcification, in an unforeseen way under future ocean conditions.